High EGT

[McGivern]

Hello guys,



This winter I installed Lucas Injectors and had my pump rebuilt at 165K. I run a non gated 16cm and 3 inch exhaust.



The truck runs great. I pulled my boat for the first time this weekend, and my EGT seem a bit high (my probe is oon the exit side of the turbo about 3-4 inches from the outlet). On the grades in 5th gear, I was seeing 950 degrees and about 17 pounds of boost. I have heard you shouldn't let her get above 950. Can you guys offer you thoughts?



93 Crew Cab 4X4 5spd 3. 54 35in tires 16cm Lucas Inj.

 

[Boldt's Wagon]

What was your speed and rpm? Shifting to 4th and a higher rpm will lower your EGT.

 

[McGivern]

Well, my speedo is off a bit I'm sure due to the larger tires.



But I was indicating about 67MPH and the tach was about 1900.



Mark

 

[Boldt's Wagon]

You need to get PowerWagon to respond to your question. You might have an air leak. Have you seen higher than 17 psi boost in the past?

 

[McGivern]

EGT

Yes,

I can get 24-25psi at WOT- the 17psi was just the steady-state boost while pulling the grade in 5th.



I sent Power Wagon a PM to ask his opinion too.



Mark

 

[BushWakr - RIP]

The POD's will give you higher temps for sure. They did with me.

There has been a "rough formula" around for 'figuring' your actual post-turbo temps. The formula is/was add 10*F for every 1 pound of boost, to your EGT reading. That will go up once you hit 20'ish psi.

I found that using that formula, I was actually off (low) by about 50*F in actual temps.

For example, when my post-turbo reading said 900*F at 20psi, I added 200*F for a total EGT of 1100*F...

Well, when I moved my pyro to PRE-TURBO it was actually 1150*-1160*F at 20psi with no other changes to fueling/timing etc.

If my example holds true your running at or near 1200*F at this point, after the math is done. Thats not taking into account boost in excess of 20psi either.

Keep in mind that is just my personal experience with this one, but I'll never mount a pyro post-turbo again if I want accurate readins while driving/pulling/carrying weight.

Post-turbo is good for cooldown readings though.



Bob.

 

[bflood]

I had the same problem with high EGT's and was running 25 to 27# boost. Other readers were surprised I was getting such boost but there was a downside. The short story is I advanced my timing (It was actually retarded from the factory timing mark).



I advanced it "by ear" so I can't give you real numbers but the results were significant:



Crisper response and much more power.

Max boost dropped to 19-20#

EGT's dropped 150 to 200 degrees.



I still have to watch my EGT's when pulling heavy loads (16,500# trailer load) up steep grades but rarely do I have to shift too early and back off to keep EGT's from running away. I avoid unnecessary lower RPM "lugging".



I've more tweeking to do but I'm in a reasonable "zone" now. I might go to a straight pipe (to avoid spending for a 4" exhaust). I think the pump can still be "tuned" some more.



Hope this helps!

 

[McGivern]

EGT probe location

This is good info guys.



I think I will move my EGT probe to before the turbo in the manifold.



What should the max reading be up there?





Mark

 

[bflood]

Re: EGT probe location

Originally posted by McGivern

This is good info guys.



I think I will move my EGT probe to before the turbo in the manifold.



What should the max reading be up there?





Mark

My understanding is you want to keep below 1250 degrees F on pre-turbo temp readings.



Search the threads and you will find tips on drilling & tapping your manifold for the probe. Watch out for the middle web casting. I drilled & tapped right in the middle of the web (by accident) so I'm getting a combined reading from both the front and rear header banks. You could do this too but its risky and I'm not sure it really gives any real benefit. In any case, I recommend you remove the turbo first so you can see what you are doing and especially to remove metal chips.



Have fun!

 

[Bob Beauchaine]

I read my egt's pre-turbo and the highest I've seen, which was a 1min. spike, was 1150 pulling my trailer up Cabbage hill in 4th. That was before my 230 pump went in. My temps are now running 100 to 150 lower and the truck has a LOT more power.

Happy trails

Bob

 

[BushWakr - RIP]

Bob Beauchaine,



Who's 230 pump are you using. Was that a 'work-up' by one of the perf. shops?

How much over fueling is it running?

Have you dyno'd the results of that pump performance yet?



Thanks,



Bob

 

[Bob Beauchaine]

BushWaker

The pump was built by Wentland Diesel in Milton Freewater OR - Power Wagon's former employer. I can't tell you how much fuel it's running but it's very strong. I have not been able to get it dynoed as yet but that is on my "short list"

I've been in PW's and feel that mine is stronger. With the PW injectors I feel I will dyno at about 250 hp and 500+lb. ft of torque. If I were to switch to the POD injectors I would probably go even higher. I can make smoke if I want to but rarely do. I am happy with my mileage and the trucks ability to haul a$$ and haul a load.

Happy trails

Bob